Improvement in grate-bars



UNITED STATES PATENT OFFICE.

WILLIAM RANDALL, OF SALEM, MASSACHUSETTS.

IMPROVEMENT IN GRATE-BARS.

Specification forming part of Letters Patent No. 86,862 dated February9, 1869.

To all whom it may concern Be it known that I, WILLIAM RANDALL, ofSalem, in the county of Essex and State of Massachusetts, have inventedcertain new and useful Improvements in Grate-Bars; and I do herebydeclare that the following is a full, clear, and exact descriptionthereof, reference being had to the accompanying drawings, making partof this specification, and to the letters of reference marked thereon,like letters indicating like parts wherever they occur.

To enable others skilled in the art to construct and use my invention, Iwill proceed to describe it.

My invention consists in a novel construction of a grate-bar for use infurnaces, whereby the air is allowed free access to the burning fuelover the entire surface of the grate, the clogging of the bars morefully prevented, and the bar rendered less liable to be burned out.

Figure l is a side elevation of a bar, with a portion broken away toshow the interior. Fig. 2 is a top-plan view. Fig. 3 is a transversevertical section, taken on the line 3 y of Figs. 1 and 2. Fig. 4 is asimilar view, taken on the line 2 2, Figs. 1 and 2.

My improved bar is made of cast-iron; and consists of an upper ormainportion, A, which is made straight, of any required length, andnearly rectangular in cross -section, with a groove or concavityextending along its upper surface, as represented in Figs. 2 and 3..

Through this part A a series of vertical openings or air-passages; a, isformed, as shown in Figs. 2 and 4, which passages are wider at bottomthan at the top, as represented in Fig. 4.

Between these passages to a series of solid portions, 0, is left, whichextend down some distance below the lower side of the part A, where theyare united toasecond part or bar, B, which extends the entire length ofthe bar, with the exception of a short space at each end, asrepresentedin Fig. 1. Through each of these solid portions 0 a hole orair-passage, 6, extends longi tudinally, as shown in Fig. 1, where theside of the part A is broken away, these longitudinal passages ethusconnecting the vertical passages a all through the bar.

The upper edge of the lower part, B, is beveled between each of theconnecting parts 0, as represented at n in Figs. 1 and 4, thus forming acomparatively thin or narrow edge, upon which the ashes and clinker thatmay fall through the passages 0 cannot lodge or accumulate to choke upthe air-passages. By this means, also, the lower portion of the passagesto on each side of B is enlarged, so as to facilitate the discharge ofthe ashes, &c., from above.

The part B, being thus constructed and united to the part A by the necksor solid portions 0, serves to brace the upper portion, A, and preventsit from bending or warping vertically when hot, the whole thus forming,as it were, a trussed or braced bar.

By this method of constructing a grate-bar it will be seen that a veryfree admission of air from below is permitted, the air rushing upthrough the spaces A, as well as between the adjoining bars, over thewhole surface of the grate, and is thus thoroughly distrib uted andbrought in to immediate contact with the burning fuel over its wholesurface. By this means, also, the air is brought into contact with alarge amount of the surface of the bar, by which two beneficial objectsare accomplished at the same time: First, the bar is cooled andprevented from burning out as rapidly as it otherwise would; and,second, the cold air is heated by its contact with the surface of thehot bar as it passes through the openings at and along the passages e,and is thereby in a better condition for supporting combustion.

As the fuel is consumed, the ashes and dcbris produced dischargethemselves through the passages to and between the bars, the peculiarform of the passages to permitting anything that will enter them fromabove to pass out freely below.

Experiments have demonstrated the fact that a grate composed of barsconstructed on this plan will last longer, clear itself better, andconsume the fuel more economically than those heretofore in use.

I am aware that perforated bars have before been used in grates ofvarious kinds, and therefore I do not claim such irrespective of myspecial plan of construction; but,

Having thus described my invention, what I claim is- A grate-barconsisting of the parts A and B, constructed and united as hereindescribed, with the air-passages a and 0, arranged in the manner setforth.

IVILLIAM RANDALL.

Witnesses Enwnnn P. KIMBALL, CHARLES A. KIMBALL.

